diff --git a/linux-atm-C99.patch b/linux-atm-C99.patch
new file mode 100644
index 0000000..39a93bb
--- /dev/null
+++ b/linux-atm-C99.patch
@@ -0,0 +1,13 @@
+Index: linux-atm-2.5.2/src/led/conn.c
+===================================================================
+--- linux-atm-2.5.2.orig/src/led/conn.c
++++ linux-atm-2.5.2/src/led/conn.c
+@@ -405,7 +405,7 @@ Conn_t *accept_conn(Conn_t *conn)
+ {
+         Conn_t *new;
+         struct sockaddr_atmsvc addr;
+-        size_t len;
++        socklen_t len;
+         int fd;
+         char buff[MAX_ATM_ADDR_LEN+1];
+ 
diff --git a/linux-atm.changes b/linux-atm.changes
index 58af503..4afc5e7 100644
--- a/linux-atm.changes
+++ b/linux-atm.changes
@@ -1,3 +1,11 @@
+-------------------------------------------------------------------
+Fri Jul 12 09:56:48 UTC 2024 - Martin Jambor <mjambor@suse.com>
+
+- Add linux-atm-C99.patch to fix a wrong type being passed to
+  functionaccept which violates C99 rules and causes compilation to
+  fail with GCC 14 (and IMHO can cause wrong behavior on big-endian
+  systems).  [boo#1221006]
+
 -------------------------------------------------------------------
 Wed Jun  2 17:51:26 UTC 2021 - Callum Farmer <gmbr3@opensuse.org>
 
diff --git a/linux-atm.spec b/linux-atm.spec
index 43814f7..3099b48 100644
--- a/linux-atm.spec
+++ b/linux-atm.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package linux-atm
 #
-# Copyright (c) 2021 SUSE LLC
+# Copyright (c) 2024 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -15,6 +15,7 @@
 # Please submit bugfixes or comments via https://bugs.opensuse.org/
 #
 
+
 %if %{undefined _firmwaredir}
 %define _firmwaredir /lib/firmware
 %endif
@@ -37,11 +38,14 @@ Patch2:         linux-atm-2.5.2-fix-header-conflict.patch
 Patch3:         linux-atm-2.5.2-remove-headers-crude-hack.patch
 # PATCH-FIX-UPSTREAM fix-build-after-y2038-changes-in-glibc.patch -- fix build after y2038 changes in glibc
 Patch4:         fix-build-after-y2038-changes-in-glibc.patch
-BuildRequires:  bison
+# PATCH-FIX-UPSTREAM linux-atm-C99.patch -- fix passing wrong type to accept
+Patch5:         linux-atm-C99.patch
+
 BuildRequires:  autoconf
-BuildRequires:  libtool
+BuildRequires:  bison
 BuildRequires:  flex
 BuildRequires:  glibc-devel
+BuildRequires:  libtool
 
 %description
 Tools to support ATM (Asynchronous Transfer Mode) networking.